Small gun perforator for wells



Dec. 29, 1953 T. o. ALLEN SMALL GUN PERFORATOR FOR WELLS Filed Sept. 11, 1950 A I I I42 4 5. 7 4 3 8 f, I, I 2 I I NM 1 6 7 v I M K) T .w v w 0 I m 2 & .5 2

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} INVENTOR. Thomas 0. Allen,

A TTORNE Y- Patented Dec. 29,1953

UNITED STATES PATENT GE'FEQE SMALL GUN PEBFORATOR FOR WELLS Thomas 0. Allen, Bellaire, Tex., assignor, by mesne assignments, to Standard Oil Development Company, Elizabeth, N. J., a corporation of Delaware Application September 11, 1950, Serial No. 184,164 Claims. (01. 164--0.5)

This invention relates to guns for perforating position for firing to perforate the casing in the pipe in oil wells or the like and more particularly well and, if desired, again brought back to a verto guns which are small enough to run through tical position for retrieving through the tubing.

tubing in a well for perforating casing beneath The objects of the invention will be apparent the tubing. from the following description taken in connec- Guns and explosives have long been used for ion with th a ompan ng dr w in whi h: perforating casing in oil wells and the art is Well Fig. 1 is a fragmentary Verti al cross-Sect onal developed. As commonly constructed the barrels View of tubing in a well bore with a gun perforaof guns used for such purposes are fixed horitor constructed in accordance with the invention zontally in a carriage and these barrels approach being lowered through it. in length, as far as is practical, the diameter of Fig. 2 is a fragmentary view in vertical crossthe casing so as to obtain the maximum fire section of casing in a well bore and showing the power. If shaped charges of explosives ar used lower portion of the tubing of Fig. 1 with the gun instead of guns which fire bullets, these also have perforator of Fig. 1 emerging therefrom and been fixed in a carriage or gun body. Even under taking its initial hinged position in the casing the best conditions, effective perforation of oil due to gravity.

well casing and the cement which usually sur- Fig. 3 is a fragmentary view in vertical crossrounds it, is diflicult to accomplish, and since the ection of the c s ng u in n n p r t r size of the gun or explosive is important, casing of Figs. 1 and 2 with the latter shown in its firin perforators as conventionally used heretofore 26 position in the casing.

have not been run into the well through tubing Fig. 4 is a side view of the upper part of the gun or other pipe smaller in diameter than the casperforator of Figs. 1 to 3 with some of the upper ing. or control section cut away to show the internal It has recently been proposed to perform cerconstruction of the mechanism for stacking the tain operations including the perforating of casgun sections.

ing in an oil well while tubing is in it. See for Fig. 5 is a side view of two of the gun sections example epplication of Theodore A. Huber, Serial of the gun perforator of Figs. 1 to 4, the View No. 133,025, filed December 15, 1949, for Method being from the opposite side thereof than that of Completing and Repairing Oil Wells where shown in Fig. 3 and illustrating the wiring of the the use of a casing perforating gun capable of gun sections.

being run through tubing is required. Large sav- Fig. 6 is a transverse cross-sectional view of the ings in time and cost can be effected in this Way gun sections of Fig. 5, the View being takefon if effective perforation can be accomplished. the line 6-6 thereof.

In accordance with application Serial No. Fig. 7 is a perspectiye/view of the muzzle end 184,161, filed September 11, 1950, by Theodore A. 3.5 of the lower gun sefation of the perforator of Huber, now Patent No. 2,639,770, it is proposed to FigsQ/top?" solve the problem of providing effective firing 'Fig. 8 is a view of a section of a gun which may power to perforate casing with an assembly which be used instead of the sections of Figs. 1 to '7, and is run into and out of the well thrdu gh tubing illustrating the use of shaped charges of exploby arranging the gunsin their carriage or gun so sives instead of bullets in the gun.

body on unions and by providing means for Referring to the drawings in detail and first etatifilitm from the vertical positions which to Figs. 1 to 7, it will be seen that the casing of they occupy while being lowered into the well, an 011 well is there shown at 12. A tubing I3 is into horizontal firing positions. Inasmuch as the positioned in the we1l with its lower end above guns may be fired by electricity, Huber proposed as the portion of the casing whlch is to be perfoto employ an electric motor to rotate them exactly a a ow 1 Flgs- 2 and 3. the right amount. Within the tubing 13, as shown in Fig. 1 and In accordance with the present invention, it is beneath it, as shown in Figs. 2 and 3, is a gun proposed to provide a structure in which gun perforator made of a number of gun sections it barrels or shaped charges of explosive are fixed and a control section I6 which are lowered into in position in the carriage or gun body but the the well on a cable Hi. This perforator be gun body itself is made in sections which are made of steel and each section E lis of cyl ndrical hinged together on alternate sides so that they shape and of a length greater than the diameter may be run into the well bore through tubing in of the tubing l3 and only slightly less than the a vertical position, then swung into a horizontal diameter of the caslng l2. They are fastened together on alternate sides by hinges Hi. In order for these sections it to be lowered into the well through the tubing, it is necessary that they be held nearly in a vertical position as shown in Fig. 1. After they pass out of the bottom of the tubing gravity causes them to deflect slightly as shown in Fig. 2 and this slight or initial deflection then causes the control section is of the gun to function to cause the sections to stack as shown in Fig. 3.

The details of the control section It of the gun are shown in Fig. 4. As there illustrated, a long compression spring H is mounted in a longitudinally extending chamber IE. A tension spring could be used instead of this compression spring, as will be apparent to those skilled in the art, and the arrangement shown is to be considered as for purposes of illustrating only the, basic principles of the invention.

A button it rests upon the top of the spring I! and is connected to a wire 25 which extends out of the lower part of the chamber l3 and is connected across the muzzle of the lower one of the gun section i as shown in Figs. 2 and '7.

Also associated with the upper section 16 is a suitable latch for holding the spring I? compressed while the gun is being lowered through the tubing This consists of a catch 22 pivoted to the section it as shown at 23 and adapted to engage the button hold it down when the button is brought below it and the catch rotated to the left, as viewed in Fig. l.

Coupling red 2!- is connected to the catch 22 and terminates in a rider or follower 25 which is arranged to rest upon the cam surface 25 of a link 22' pivoted to the lower end of the section l6 as shown at 23 and connected by a hinge to the upper one of the gun sections Hi.

The construction is such that when the gun is being lowered down through the tubing E3, the link 23 is held substantially aligned with the section it. In this position, the rider 125 is held up and the catch ?2 is held rotated to the left so that the spring ii is held compressed.

As soon as the link passes the bottom of the tubing the parts take the position shown in Fig. 2, under the influence of gravity and when this occurs, the link rotated enough to permit the rider to move down slightly and release the catch so that the spring il forces the button 2i? upwardly exerting tension in the wire 2! and drawing the gun sections it into their stacked position as shown in Fig. 3. A coil spring 3% on the pivot pin 23 or" the link 21' may assist in releasing the spring As in dotted lines in Fig. 5, each section it may contain a bullet 3i and a charge of explosive and these may be so arranged, as illustrated, that adjacent guns fire in opposite directions. For firing the charges of explosive, as shown in Figs. 5 and 6, an electrical fuse may be employed, and an electrical conductor 3-3 may be mounted in slots in the gun sections it to convey electric current from the cable ltto the charges of explosive. The conductor 33 may extend up through the section it for making this connection.

It is within the purview of the invention to load each section it with two bullets which are discharged from opposite ends of each section, as taught in the copending application of Theodore Huber mentioned above and in that case there will be little reaction force set up in the gun sections. However, if the sections are each loaded with only one bullet, as illustrated,

4 they should have interfitting means for coupling them so as to withstand the shock or reaction forces. One way of interfitting them is to provide lugs and sockets on the sections as shown at 35 and 36.

If desired, shaped charges of explosive, such as shown at 31 in Fig. 8 may be employed instead of bullets to perforate the casing [2. In that event the entire sections it may be blown up when the explosive is fired and only the section it removed from the well bore.

In any event, since the wire 2| passes over the muzzle of the lower section is, the wire 2! will be broken when the gun is fired and the sections l4 pulled back up through the tubing.

It will thus be seen that the invention provides gun sections of adequate length to give suiiicient fire power if bullets are used or of such shape as to bring shaped charges into the proper stand-on position with respect to the casing, if they are used to perforate and still permits these sections to be lowered down through the tubing with a minimum of inconvenience.

If some obstruction is first located in the easing at the point where perforating is to take place, the wire 2 5, spring ll and the control mechanism can be eliminated since the sections can be caused to stack on the obstruction. It i also within the purview of the invention to lower the sections it to the bottom of the well to stack them. They may then be latched together by suitable means and brought up in the well to the point where the casing is to be perforated before firing them.

It is common knowledge that tubing in oil wells is often bent and long cylindrical bodies approaching the internal diameter of the tubing cannot be passed by such bends. Because of the hinged arrangement of the section of the gun of the present invention, this difiiculty is obviated.

While only two embodiments of the invention are shown and described it will be obvious that various changes may be made without departing from the spirit of the invention or the scope of the annexed claims.

I claim:

1. A device for perforating casing in oil wells beneath tubing suspended within said casing comprising a control section; a plurality of cylindrical gun sections; hinges for hingedly connecting said sections together at their ends and for connecting the uppermost of said gun sections to said control section, alternate hinges being affixed to the ends of the gun sections at diametrically opposed points thereon in such a way as to permit the gun sections to assume a position wherein their longitudinal axes are substantially verticaland to permit said gun sections to assume a position wherein their longitudinal axes are substantially horizontal; and means carried by the control section for causing the sections to assume automatically a position for firing such that their longitudinal axes are sub stantially horizontal when the gun sections are not prevented from assuming said firing position, the cylindrical gun sections being longer in axial direction than in cross-sectional diameter, whereby said sections will pass through said tubing when arranged so that their longitudinal axes are substantially vertical and will assume a position wherein the longitudinal axes are substantially horizontal when they have cleared the lower end of the tubing.

2. The device defined in claim 1 in which each section is loaded with one bullet, a charge of explosive, and a detonator for the explosive adjacent sections being so loaded that they fire in opposite directions.

3. The device defined in claim 1, adjacent sections having interfitting means which couple them together so as to withstand the reaction forces created when they are fired.

4. A device for perforating casing in oil wells beneath tubing suspended within said casing comprising a control section, said control section carrying a movable element biased upwardly within said section; a plurality of cylindrical gun sections, the uppermost of said gun sections being hingedly connected at its upper end to said control section and the remainder of said gun sections being hingedly connected at their upper end to the lower end of the gun section immediately thereabove, the point of hinged connection at the upper end of each gun section being diametrically opposed to the point of hinged connection on the gun section immediately therebelow; and a flexible connecting means interconnecting said movable element in the control section with the end of the lowermost gun section removed from the end which is hingedly con nected, whereby the longitudinal axes of said gun sections are substantially vertical as they pass through the tubing and then assume a position such that their axes are substantially horizontal when they have been lowered to a point beneath the lower end of the tubing.

5. The arrangement defined in claim 4 in which said flexible mean is a Wire line.

THOMAS O. ALLEN.

No references cited. 

